Microwave Ablation with a Single Small-Gauge Triaxial Antenna: In Vivo Porcine Liver Model

Abstract

Purpose: To evaluate the performance of a 17-gauge triaxial antenna at microwave ablation in an in vivo porcine liver model. Materials and Methods: This study was approved by the institutional animal care and use committee. Thirteen female domestic pigs (mean weight, 45 kg) were used. Ablations were performed with a prototype microwave ablation system and triaxial antenna by using a constant, continuous-wave power of 68 W for 2 (n = 6), 3 (n = 6), 4 (n = 6), 5 (n = 6), 6 (n = 6), 7 (n = 13), 10 (n = 7), and 12 (n = 8) minutes. Animals were euthanized after ablation, livers were removed, and ablation zones were sliced and measured for size and roundness. A mixed linear model with animals modeled as random effects was used to test for significant differences in ablation zone metrics among time groups; post hoc tests were used to detect significant differences between time groups. Results: Mean ablation zone diameters ranged from 2.05 cm ± 0.23 (standard deviation) at 2 minutes to 2.59 cm ± 0.53 at 12 minute...